Intervertebral implant devices

ABSTRACT

Spinal implants for positioning between adjacent vertebrae. Some embodiments may comprise a pair of opposed sidewall surfaces, a pair of opposed frictional surfaces, a first end wall joining the pair of opposed sidewall surfaces, and a second end wall recessed at least in part and joining the pair of opposed sidewall surfaces. A fish-tailed structure may be positioned within the second end wall when viewed from one of the opposed frictional surface. The fish-tailed structure may be formed so as to extend at least substantially uninterrupted between at least one of the opposed sidewall surfaces and the opposed frictional surfaces. A retention structure, such as a hole, may be positioned within the fish-tailed structure. The hole may be configured to engage a surgical implantation device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.12/896,292, filed on Oct. 1, 2010, and titled “INTERVERTEBRAL IMPLANTDEVICE FOR A POSTERIOR INTERBODY FUSION SURGICAL PROCEDURE,” whichclaims the benefit of priority of U.S. Provisional Patent ApplicationNo. 61/248,052, filed on Oct. 2, 2009, and entitled “INTERVERTEBRALIMPLANT DEVICE FOR A POSTERIOR INTERBODY FUSION SURGICAL PROCEDURE.”Both of the aforementioned applications are incorporated by referenceherein in their entireties.

FIELD OF THE INVENTION

The present invention relates generally to an intervertebral implantdevice for a posterior interbody fusion surgical procedure.Advantageously, this intervertebral implant device is designed andconfigured such that it may be surgically implanted in the spine of apatient through a minimal access window, thereby sparing and preservingthe associated facets to the greatest degree possible.

BACKGROUND OF THE INVENTION

A variety of spinal conditions, such as compression of the spinal cordnerve roots, degenerative disc disease, herniated nucleus pulposus,spinal stenosis, and spondylolisthesis may cause moderate to severelower back and leg pain. Intervertebral or interbody fusion is asurgical procedure that is used to alleviate such lower back and legpain. In posterior lumbar interbody fusion (PLIF), two adjacentvertebral bodies of the lumbar spine are fused together by removing theaffected disc and inserting posteriorly one or more implant devices orcages that allow one or more bone grafts to grow between the twoadjacent vertebral bodies to bridge the gap left by the removed disc.Various degrees of distraction may also be provided, as required on acase-by-case basis.

One variation of the traditional PLIF technique is the transforaminalposterior lumbar interbody fusion (T-PLIF) technique. In this surgicalprocedure, an implant device or cage is inserted into the affected discspace via a unilateral (or sometimes bilateral) posterior approach,offset from the midline of the spine, by first removing portions of thefacets of the vertebrae. Advantageously, the T-PLIF technique avoidsdamage to nerve structures, such as the dura, cauda equina, and nerveroots, but the resulting transforaminal window available to remove theaffected disc, prepare the vertebral endplates, and insert the implantdevice or cage is limited laterally by soft tissue and medially by thecauda equina.

A variety of different implant devices and cages typically used for thetraditional PLIF procedure have also been used for the T-PLIF procedurewith varying degrees of success. These include threaded titanium,ceramic, and polymer cages, allograft (i.e. bone) wedges, rings, etc.However, as these devices and cages are not designed specifically forthe T-PLIF procedure, they are not shaped to be easily insertable intothe affected disc space through the narrow transforaminal window, andmay require additional retraction of the cauda equina and nerve roots.Such retraction may cause temporary or permanent nerve damage. Inaddition, some of these devices and cages, such as the threadedtitanium, ceramic, and polymer cages, suffer from the disadvantage ofrequiring drilling and tapping of the vertebral endplates prior toinsertion. Further, the incidence of subsidence in long term use is notknown for such devices and cages. Finally, the restoration of lordosis,i.e. the natural curvature of the lumbar spine, is very difficult toachieve when a cylindrical or square titanium, ceramic, or polymer cageis used.

Thus, there is a need in the art for an intervertebral implant devicefor a posterior interbody fusion surgical procedure that is configuredsuch that it may be surgically implanted in the spine of a patientthrough a minimal access window, thereby sparing and preserving theassociated facets to the greatest degree possible.

BRIEF SUMMARY OF THE INVENTION

In various exemplary embodiments, the present invention provides anintervertebral implant device for a posterior interbody fusion surgicalprocedure. Advantageously, this intervertebral implant device isconfigured such that it may be surgically implanted in the spine of apatient through a minimal access window, thereby sparing and preservingthe associated facets to the greatest degree possible.

In one exemplary embodiment, the present invention provides anintervertebral implant device, including: a pair of substantiallyparallel opposed arcuate surfaces; a pair of substantially parallelopposed frictional surfaces each including a plurality of raisedstructures; a substantially curved end wall joining the pair of parallelopposed arcuate surfaces; and a substantially recessed end wall joiningthe pair of parallel opposed arcuate surfaces; wherein theintervertebral implant device defines one or more voids in which a bonegraft material is selectively disposed. The substantially recessed endwall is configured to selectively and pivotably receive one or moresurgical implantation devices. The substantially curved end wallincludes one or more smoothed edges. The substantially recessed end wallincludes a first wall portion and a second wall portion arranged at anangle to one another and collectively forming a fish-tailed structure.The substantially recessed end wall includes one or more of a hole and arecess configured to selectively receive a surgical tool. The one ormore voids defined by the intervertebral implant device pass through oneor more of the pair of substantially parallel opposed arcuate surfacesand the pair of substantially parallel opposed frictional surfaces. Theintervertebral implant device is configured to be selectively disposedin an intervertebral space through an access window formed through bonyand soft tissue structures to either the left or right of a centerlineof a spine.

In another exemplary embodiment, the present invention provides asurgical method for implanting an intervertebral implant device,including: providing an intervertebral implant device, including: a pairof substantially parallel opposed arcuate surfaces; a pair ofsubstantially parallel opposed frictional surfaces each including aplurality of raised structures; a substantially curved end wall joiningthe pair of parallel opposed arcuate surfaces; and a substantiallyrecessed end wall joining the pair of parallel opposed arcuate surfaces;wherein the intervertebral implant device defines one or more voids inwhich a bone graft material is selectively disposed; and disposing theintervertebral implant device within an intervertebral space through anaccess window formed adjacent to a facet joint of a spine of a patient.The substantially recessed end wall is configured to selectively andpivotably receive one or more surgical implantation devices. Thesubstantially curved end wall includes one or more smoothed edges. Thesubstantially recessed end wall includes a first wall portion and asecond wall portion arranged at an angle to one another and collectivelyforming a fish-tailed structure. The substantially recessed end wallincludes one or more of a hole and a recess configured to selectivelyreceive a surgical tool. The one or more voids defined by theintervertebral implant device pass through one or more of the pair ofsubstantially parallel opposed arcuate surfaces and the pair ofsubstantially parallel opposed frictional surfaces. The intervertebralimplant device is configured to be selectively disposed in anintervertebral space through the access window formed through bony andsoft tissue structures to either the left or right of a centerline of aspine.

In a further exemplary embodiment, the present invention provides asurgical method for implanting an intervertebral implant device,including: forming an access window through bony and soft tissuestructures to either the left or right of a centerline of a spine;passing bone graft material through the access window and into anadjacent intervertebral space; disposing bone graft material in anintervertebral implant device; passing the intervertebral implant devicethrough the access window and into the adjacent intervertebral space;and positioning the intervertebral implant device within theintervertebral space. The intervertebral implant device includes: a pairof substantially parallel opposed arcuate surfaces; a pair ofsubstantially parallel opposed frictional surfaces each including aplurality of raised structures; a substantially curved end wall joiningthe pair of parallel opposed arcuate surfaces; and a substantiallyrecessed end wall joining the pair of parallel opposed arcuate surfaces.The intervertebral implant device defines one or more voids in which thebone graft material is selectively disposed.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated and described herein with referenceto the various drawings, in which like reference numbers are used todenote like device components/method steps, as appropriate, and inwhich:

FIG. 1 is a perspective diagram illustrating one exemplary embodiment ofthe intervertebral implant device of the present invention;

FIG. 2 is a planar diagram also illustrating one exemplary embodiment ofthe intervertebral implant device of the present invention;

FIG. 3 is a perspective diagram illustrating one exemplary embodiment ofa placement device for use with the intervertebral implant device of thepresent invention;

FIG. 4 is a perspective diagram illustrating one exemplary embodiment ofa positioning device for use with the intervertebral implant device ofthe present invention;

FIG. 5 is a perspective diagram illustrating one exemplary embodiment ofa tamping device for use with the intervertebral implant device of thepresent invention;

FIG. 6 is a series of perspective drawings illustrating successive stepsin one exemplary embodiment of a method for surgically implanting theintervertebral implant device of the present invention—illustrating theremoval of a small amount of bony material adjacent to a facet joint ofthe spine in order to form an access portal through which theintervertebral implant device of the present invention may be insertedinto an intervertebral space;

FIG. 7 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—again illustrating the removal of a small amount of bonymaterial adjacent to a facet joint of the spine in order to form anaccess portal through which the intervertebral implant device of thepresent invention may be inserted into an intervertebral space;

FIG. 8 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—again illustrating the removal of a small amount of bonymaterial adjacent to a facet joint of the spine in order to form anaccess portal through which the intervertebral implant device of thepresent invention may be inserted into an intervertebral space;

FIG. 9 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—illustrating the removal of a small amount of soft tissuematerial adjacent to a facet joint of the spine in order to form anaccess portal through which the intervertebral implant device of thepresent invention may be inserted into an intervertebral space;

FIG. 10 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—again illustrating the removal of a small amount of softtissue material adjacent to a facet joint of the spine in order to forman access portal through which the intervertebral implant device of thepresent invention may be inserted into an intervertebral space;

FIG. 11 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—again illustrating the removal of a small amount of softtissue material adjacent to a facet joint of the spine in order to forman access portal through which the intervertebral implant device of thepresent invention may be inserted into an intervertebral space;

FIG. 12 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—illustrating the sizing of the intervertebral space prior tothe insertion of the intervertebral implant device of the presentinvention;

FIG. 13 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—illustrating the insertion of bone graft material into theintervertebral space prior to the insertion of the intervertebralimplant device of the present invention;

FIG. 14 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—illustrating the insertion of the intervertebral implantdevice of the present invention into the intervertebral space using theplacement device of the present invention;

FIG. 15 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—illustrating the insertion and positioning of theintervertebral implant device of the present invention into and withinthe intervertebral space using the positioning device of the presentinvention;

FIG. 16 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—again illustrating the insertion and positioning of theintervertebral implant device of the present invention into and withinthe intervertebral space using the positioning device of the presentinvention;

FIG. 17 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—illustrating the insertion and positioning of theintervertebral implant device of the present invention into and withinthe intervertebral space using the tamping device of the presentinvention;

FIG. 18 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—again illustrating the insertion and positioning of theintervertebral implant device of the present invention into and withinthe intervertebral space again using the tamping device of the presentinvention; and

FIG. 19 is a final perspective drawing illustrating a continuingsuccessive step in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device of the presentinvention—illustrating the final placement of the intervertebral implantdevice in the intervertebral space, along with the associated bone graftmaterial.

DETAILED DESCRIPTION OF THE INVENTION

In various exemplary embodiments, the present invention provides anintervertebral implant device for a posterior interbody fusion surgicalprocedure. Advantageously, this intervertebral implant device isconfigured such that it may be surgically implanted in the spine of apatient through a minimal access window, thereby sparing and preservingthe associated facets to the greatest degree possible.

FIG. 1 is a perspective diagram illustrating one exemplary embodiment ofthe intervertebral implant device 10 of the present invention. In thisexemplary embodiment, the intervertebral implant device 10 includes apair of substantially parallel opposed arcuate surfaces 12 and a pair ofsubstantially parallel opposed frictional surfaces 14 including aplurality of raised structures 16, such as teeth, grooves or the like.The pair of opposed arcuate surfaces 12 and the pair of opposedfrictional surfaces 14 together form a prismatic structure that has aslight curve in one plane. This prismatic structure has overalldimensions on the order of tens of mm in length, tens of mm in width,and several mm in thickness, such that it may be disposed in a range ofintervertebral spaces and provide a range of distraction, if so desired.Preferably, the prismatic structure defines one or more voids 18 inwhich a bone graft material or the like may selectively be disposed.These voids 18 may be internal to the prismatic structure, pass throughthe pair of opposed arcuate surfaces 12, pass through the pair ofopposed frictional surfaces 14, and/or be in communication with one ormore recesses 19 manufactured into the exterior of the pair of opposedarcuate surfaces 12 and/or the pair of opposed frictional surfaces 14.These voids 18 and/or recesses 19 help promote bony ingrowth thateventually fuses the intervertebral implant device 10 in theintervertebral space. One end of the intervertebral implant device 10includes a rounded or partially-rounded end wall 20, that preferably hassmoothed edges 21 to prevent it from catching on or damaging anyanatomical structures during insertion. The other end of theintervertebral implant device 10 includes a recessed or fish-tailed endwall 22. The fish-tailed end wall 22 defines a hole and/or otherretention structures 24 for selectively and pivotably receiving one ormore surgical implantation devices. In this exemplary embodiment, thefish-tailed end wall 22 includes a pair of angularly disposed walls 23,25 joined by a central flat wall 27. The first of the pair of angularlydisposed walls 23 protrudes from the prismatic structure to a greaterdegree than the second of the pair of angularly disposed walls 25,although other suitable configurations may be utilized. In thisexemplary embodiment, the retention structures 24 for selectively andpivotably receiving one or more surgical implantation devices arecoextensive with the one or more recesses 19 manufactured into theexterior of the pair of opposed arcuate surfaces 12 and/or the pair ofopposed frictional surfaces 14. The intervertebral implant device 10 maybe made of any suitable surgically-implantable material, such as ametallic material, a ceramic material, a polymeric material, or anallograft material, and may have any suitable dimensions such that itmay be disposed within an intervertebral space of the spine of a patientwhile providing a desired degree of distraction.

Advantageously, the configuration of the pair of substantially parallelopposed arcuate surfaces 12 and the pair of substantially parallelopposed frictional surfaces 14 provides a surgical implant that may beplaced into the intervertebral space through a narrow transforaminalwindow or the like that is disposed either to the left or the right ofthe spinal centerline. This is due to the fact that the prismaticstructure is symmetric top-to-bottom. Once placed, the plurality ofraised structures 16 of the pair of substantially parallel opposedfrictional surfaces 14 engage the intervertebral endplates, securing theintervertebral implant device 10 snugly in place.

FIG. 2 is a planar diagram also illustrating one exemplary embodiment ofthe intervertebral implant device 10 of the present invention. Again, inthis exemplary embodiment, the intervertebral implant device 10 includesa pair of substantially parallel opposed arcuate surfaces 12 and a pairof substantially parallel opposed frictional surfaces 14 including aplurality of raised structures 16, such as teeth, grooves or the like.The pair of opposed arcuate surfaces 12 and the pair of opposedfrictional surfaces 14 together form a prismatic structure that has aslight curve in one plane. This prismatic structure has overalldimensions on the order of tens of mm in length, tens of mm in width,and several mm in thickness, such that it may be disposed in a range ofintervertebral spaces and provide a range of distraction, if so desired.Preferably, the prismatic structure defines one or more voids 18 inwhich a bone graft material or the like may selectively be disposed.These voids 18 may be internal to the prismatic structure, pass throughthe pair of opposed arcuate surfaces 12, pass through the pair ofopposed frictional surfaces 14, and/or be in communication with one ormore recesses 19 (FIG. 1) manufactured into the exterior of the pair ofopposed arcuate surfaces 12 and/or the pair of opposed frictionalsurfaces 14. These voids 18 and/or recesses 19 help promote bonyingrowth that eventually fuses the intervertebral implant device 10 inthe intervertebral space. One end of the intervertebral implant device10 includes a rounded or partially—rounded end wall 20, that preferablyhas smoothed edges 21 to prevent it from catching on or damaging anyanatomical structures during insertion. The other end of theintervertebral implant device 10 includes a recessed or fish-tailed endwall 22. The fish-tailed end wall 22 defines a hole and/or otherretention structures 24 (FIG. 1) for selectively and pivotably receivingone or more surgical implantation devices. In this exemplary embodiment,the fish-tailed end wall 22 includes a pair of angularly disposed walls23, 25 joined by a central flat wall 27 (FIG. 1). The first of the pairof angularly disposed walls 23 protrudes from the prismatic structure toa greater degree than the second of the pair of angularly disposed walls25, although other suitable configurations may be utilized. In thisexemplary embodiment, the retention structures 24 for selectively andpivotably receiving one or more surgical implantation devices arecoextensive with the one or more recesses 19 manufactured into theexterior of the pair of opposed arcuate surfaces 12 and/or the pair ofopposed frictional surfaces 14. The intervertebral implant device 10 maybe made of any suitable surgically-implantable material, such as ametallic material, a ceramic material, a polymeric material, or anallograft material, and may have any suitable dimensions such that itmay be disposed within an intervertebral space of the spine of a patientwhile providing a desired degree of distraction.

FIG. 3 is a perspective diagram illustrating one exemplary embodiment ofa placement device 30 for use with the intervertebral implant device 10(FIGS. 1 and 2) of the present invention. The placement device 30includes a handle portion 32 and an engaging portion 34. Preferably, theengaging portion 34 includes a pillar and/or fin structures forselectively engaging the hole and/or other retention structures 24(FIG. 1) of the intervertebral implant device 10, such that theintervertebral implant device 10 is selectively held by the placementdevice 30 while being inserted into the intervertebral space.

FIG. 4 is a perspective diagram illustrating one exemplary embodiment ofa positioning device 40 for use with the intervertebral implant device10 (FIGS. 1 and 2) of the present invention. The positioning device 40includes a handle portion 42 and an engaging portion 44. Preferably, theengaging portion 44 includes a fish-tailed feature for selectivelyengaging the fish-tailed end wall 22 (FIGS. 1 and 2) of theintervertebral implant device 10, such that the intervertebral implantdevice 10 is selectively guided by the positioning device 40 onceinserted into the intervertebral space. Accordingly, the shaft 46 of thepositioning device 40 includes a curved portion 48, allowing thepositioning device 40 to be guided through a narrow transforaminalwindow (either left or right) and into the intervertebral space while incontact with the intervertebral implant device 10.

FIG. 5 is a perspective diagram illustrating one exemplary embodiment ofa tamping device 50 for use with the intervertebral implant device 10(FIGS. 1 and 2) of the present invention. The tamping device 50 includesa handle portion 52 and an engaging portion 54. Preferably, the engagingportion 54 includes one or more friction structures for selectivelyengaging the fish-tailed end wall 22 (FIGS. 1 and 2) of theintervertebral implant device 10, such that the intervertebral implantdevice 10 is selectively driven by the tamping device 50 while beingpositioned and seated in the intervertebral space.

FIG. 6 is a series of perspective drawings illustrating successive stepsin one exemplary embodiment of a method for surgically implanting theintervertebral implant device 10 (FIGS. 1 and 2) of the presentinvention-illustrating the removal of a small amount of bony material 60adjacent to a facet joint 100 of the spine in order to form an accessportal through which the intervertebral implant device 10 of the presentinvention may be inserted into an intervertebral space.

FIG. 7 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 (FIGS. 1 and 2) of thepresent invention—again illustrating the removal of a small amount ofbony material 70 adjacent to a facet joint 100 of the spine in order toform an access portal through which the intervertebral implant device 10of the present invention may be inserted into an intervertebral space.

FIG. 8 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 (FIGS. 1 and 2) of thepresent invention—again illustrating the removal of a small amount ofbony material 80 adjacent to a facet joint 100 of the spine in order toform an access portal through which the intervertebral implant device 10of the present invention may be inserted into an intervertebral space.

FIG. 9 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 (FIGS. 1 and 2) of thepresent invention—illustrating the removal of a small amount of softtissue material 90 adjacent to a facet joint 100 of the spine in orderto form an access portal through which the intervertebral implant device10 of the present invention may be inserted into an intervertebralspace.

FIG. 10 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 (FIGS. 1 and 2) of thepresent invention—again illustrating the removal of a small amount ofsoft tissue material 110 adjacent to a facet joint 100 of the spine inorder to form an access portal through which the intervertebral implantdevice 10 of the present invention may be inserted into anintervertebral space.

FIG. 11 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 (FIGS. 1 and 2) of thepresent invention—again illustrating the removal of a small amount ofsoft tissue material 111 adjacent to a facet joint 100 of the spine inorder to form an access portal through which the intervertebral implantdevice 10 of the present invention may be inserted into anintervertebral space.

FIG. 12 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 (FIGS. 1 and 2) of thepresent invention—illustrating the sizing of the narrow transforaminalwindow 119 and intervertebral space 200 using a sizing device 120 priorto the insertion of the intervertebral implant device 10 of the presentinvention.

FIG. 13 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 of the presentinvention—illustrating the insertion of bone graft material 130 into theintervertebral space 200 prior to the insertion of the intervertebralimplant device 10 of the present invention. In this exemplaryembodiment, the intervertebral implant device is also packed with bonegraft material 130.

FIG. 14 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 of the presentinvention—illustrating the insertion of the intervertebral implantdevice 10 of the present invention into the intervertebral space 200using the placement device 30 (FIG. 3) of the present invention, forexample.

FIG. 15 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 of the presentinvention—illustrating the insertion and positioning of theintervertebral implant device 10 of the present invention into andwithin the intervertebral space 200 using the positioning device 40 ofthe present invention.

FIG. 16 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 of the presentinvention—again illustrating the insertion and positioning of theintervertebral implant device 10 of the present invention into andwithin the intervertebral space 200 using the positioning device 40 ofthe present invention.

FIG. 17 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 of the presentinvention—illustrating the insertion and positioning of theintervertebral implant device 10 of the present invention into andwithin the intervertebral space 200 using the tamping device 50 of thepresent invention.

FIG. 18 is a series of perspective drawings illustrating continuingsuccessive steps in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 of the presentinvention—again illustrating the insertion and positioning of theintervertebral implant device 10 of the present invention into andwithin the intervertebral space 200 again using the tamping device 50 ofthe present invention.

FIG. 19 is a final perspective drawing illustrating a continuingsuccessive step in one exemplary embodiment of a method for surgicallyimplanting the intervertebral implant device 10 of the presentinvention—illustrating the final placement of the intervertebral implantdevice 10 in the intervertebral space 200, along with the associatedbone graft material 130.

Although the present invention has been illustrated and described hereinwith reference to preferred embodiments and specific examples thereof,it will be readily apparent to those of ordinary skill in the art thatother embodiments and examples may perform similar functions and/orachieve like results. All such equivalent embodiments and examples arewithin the spirit and scope of the present invention, are contemplatedthereby, and are intended to be covered by the following claims. In thisrespect, this specification is intended to be exemplary and non-limitingto the greatest extent possible.

1. A spinal implant, comprising: a first sidewall; a second sidewallopposite from the first sidewall; a first frictional surface configuredfor engaging a first vertebra; a second frictional surface configure forengaging a second vertebra adjacent to the first vertebra; a first endwall joining the first sidewall and the second sidewall at a first endof the spinal implant; a second end wall joining the first sidewall andthe second sidewall at a second end of the spinal implant opposite fromthe first end; and a retention structure positioned within the secondend wall; wherein the second end wall comprises a recess formed by afirst wall portion and a second wall portion arranged at an angle to oneanother to form a fish-tailed structure; wherein the retention structureis positioned within the fish-tailed structure; and wherein theretention structure is configured to engage a surgical implantationdevice.
 2. The spinal implant of claim 1, wherein the retentionstructure comprises a hole.
 3. The spinal implant of claim 2, whereinthe hole comprises a threaded hole.
 4. The spinal implant of claim 2,wherein the hole is positioned at a location at least substantiallyequidistant from the first frictional surface and the second frictionalsurface.
 5. The spinal implant of claim 4, wherein the hole ispositioned at a location at least substantially equidistant from thefirst sidewall and the second sidewall.
 6. The spinal implant of claim1, wherein the fish-tailed structure is formed so as to extend at leastsubstantially all of the way along at least one dimension of the secondend wall.
 7. The spinal implant of claim 6, wherein the fish-tailedstructure is formed so as to extend at least substantially all of theway between the first frictional surface and the second frictionalsurface.
 8. The spinal implant of claim 7, wherein the first wallportion extends from and joins with the first sidewall, and wherein thesecond wall portion extends from and joins with the second sidewall, soas to form the fish-tailed structure.
 9. The spinal implant of claim 1,wherein the first sidewall and the second sidewall comprise opposedarcuate surfaces.
 10. The spinal implant of claim 1, wherein the firstfrictional surface comprises a plurality of raised structures, andwherein the second frictional surface comprises a plurality of raisedstructures.
 11. An intervertebral implant device, comprising: a pair ofopposed sidewall surfaces; a pair of opposed frictional surfaces; afirst end wall joining the pair of opposed sidewall surfaces; a secondend wall recessed at least in part and joining the pair of opposedsidewall surfaces; a fish-tailed structure positioned within the secondend wall when viewed from one of the opposed frictional surfaces,wherein the fish-tailed structure is formed so as to extend at leastsubstantially uninterrupted between at least one of the opposed sidewallsurfaces and the opposed frictional surfaces; and a hole positionedwithin the fish-tailed structure, wherein the hole is configured toengage a surgical implantation device.
 12. The intervertebral implantdevice of claim 11, wherein the fish-tailed structure is formed so as toextend at least substantially uninterrupted between the opposed sidewallsurfaces.
 13. The intervertebral implant device of claim 11, wherein thefish-tailed structure is formed so as to extend at least substantiallyuninterrupted between the opposed frictional surfaces.
 14. Theintervertebral implant device of claim 11, wherein the second end wallcomprises a first wall portion and a second wall portion arranged at anangle to one another and collectively forming the fish-tailed structure.15. The intervertebral implant device of claim 14, wherein thefish-tailed structure is formed such that the first wall portion and thesecond wall portion extend from one another at an angle greater thanninety degrees.
 16. The intervertebral implant device of claim 14,wherein the fish-tailed structure further comprises a third wall portionjoining the first wall portion and the second wall portion.
 17. Theintervertebral implant device of claim 16, wherein the third wallportion comprises a flat wall.
 18. The intervertebral implant device ofclaim 11, wherein the hole is positioned centrally within the second endwall with respect to the fish-tailed structure.
 19. An intervertebralimplant device, comprising: a pair of opposed sidewall surfaces; a pairof opposed frictional surfaces each comprising a plurality of raisedstructures; a first end wall joining the pair of opposed arcuatesurfaces; a second end wall recessed at least in part and joining thepair of opposed arcuate surfaces, the second end wall comprising a firstwall portion and a second wall portion arranged at an angle to oneanother and collectively forming a fish-tailed structure when viewedfrom one of the opposed frictional surfaces, wherein the fish-tailedstructure is formed so as to extend at least substantially uninterruptedbetween the opposed frictional surfaces; and a hole positioned withinthe fish-tailed structure; wherein the hole is configured to engage asurgical implantation device; wherein the first wall portion extendsbetween the opposed frictional surfaces from an upper frictional surfaceto a lower frictional surface; and wherein the second wall portionextends between the opposed frictional surfaces from the upperfrictional surface to the lower frictional surface.
 20. Theintervertebral implant device of claim 19, wherein the fish-tailedstructure is formed so as to extend at least substantially uninterruptedbetween the opposed sidewall surfaces.